Android boot process stub

阅读更多

Android's boot up process is summarized below:

 

Stage Steps Comments

Boot-loader	-	Location: bootable\bootloader\legacy\usbloader
	init.S	Initializes stacks, zeros the BSS segment, call _main() in main.c
	main.c	Initializes hardware (clocks, board, keypad, console), creates Linux tags
		Displays "USB FastBoot". Boot from flash, or loops while usb_poll() awaits host PC connection
Linux kernel	-	Sets up the system, loads drivers, and starts running the first process init
The init process	Setup file system	Create and mount directories like /dev, /proc, /sys
	Execute init.rc	This is the boot-up script, commands are using Android-specific syntax, see readme.txt
	Setup console
	Display "A N D R O I D"	This is just a text msg written to /dev/tty0
	Zygote	Zygot process in init.rc brings up Dalvik Java VM and starts the system server
	bootanimation	Shows the animation during boot-up
Framework	….	….